The invention relates generally to turbo-machinery. In particular, the invention relates to replacing a composite airfoil used in the turbo-machinery.
Turbo-machinery may take many forms or be applied in various uses. These forms and uses may include steam turbines for power generation, gas turbines for power generation, gas turbines for aircraft propulsion and wind turbines for power generation.
In a gas turbine, typically there are numerous rotating blades and stationary vanes. The blades and vanes are arranged in alternating circumferential arrays that are spaced longitudinally along the turbine. Each of the blades and vanes includes an airfoil portion attached to a mounting portion.
During operation of a gas turbine, dirt, debris and/or moisture may contact the airfoil and result in damage, erosion and/or corrosion to the surface. This usually causes a loss of performance of the gas turbine. Generally, gas turbines for aircraft propulsion permit relatively good access to blades and vanes, so damaged ones can be removed and replaced. However, gas turbines for power generation typically do not offer such access for removing and replacing blades and vanes.
One gas turbine that can be used for power generation as disclosed in U.S. patent application Ser. Nos. 11/858,326 and 11/858,333, has a plurality of compressor and turbine stages. At least one of the compressor stages includes a composite airfoil. The composite airfoil has a mounting structure for attaching to gas turbine structure. A core extends from the mounting structure. The core is made from a material such as metal or ceramic. An airfoil portion envelopes the core and is made from an injection molded plastic material.
Accordingly, there is a need for way to repair or replace a composite airfoil for a gas turbine.